Modern vehicles typically have a windshield forward of the passenger compartment. A windshield wiper system is positioned adjacent the windshield, and includes wiper arms that support wiper blades. The wiper arms pivot over a predefined range of motion on pivot shafts so that the blades oscillate over the windshield to clear precipitation. The pivot shaft is driven by a power source, such as an electrical motor, often via a linkage system that translates the rotation of the motor shaft into oscillating motion of the wiper arms. The pivot shaft may extend further forward than other exposed portions of the windshield wiper system, and thus may receive external forces applied toward the front of the vehicle. One known windshield wiper system has a pivot shaft holder with a stress concentration feature that causes the pivot shaft holder and pivot shaft to move away from the external force. The pivot shaft holder must then be replaced, however.